Solar panels are generally well known (see, e.g., U.S. Pub. No. 2006/0283497 (Hines)). It is desirable to produce solar panels that either produce more power and/or that cost less.
To date, photovoltaic solar concentrators have generally taken one of two approaches—either build a large reflective trough or dish or a field of articulating mirrors which reflect light to a central point, where it is converted to power (such as by Solar Systems of Victoria, Australia and by Gross et al., U.S. Pat. No. 2005/0034751), or tightly pack a large number of small concentrators into a large panel which articulates rigidly to follow the sun (such as by Chen, U.S. Pub. No. 2003/0075212 or Stewart, U.S. Pub. No. 2005/0081908). See also the Matlock et al. reference (U.S. Pat. No. 4,000,734), which discloses elongated reflectors mounted for movement around a heating tube arranged in the linear focus of the reflectors and a tracking mechanism.
A recent third approach that has appeared in the prior art (Fraas et al., U.S. Pub. No. 2003/0201007) is to attempt to combine the advantages of concentration with the convenience of the form factor of an ordinary solar panel. Fraas et al, show multiple approaches that attempt to solve the cost/performance/convenience problem.
An approach to produce a flat solar concentrator was to place rows of small concentrators in a “lazy susan” rotating ring (Cluff, U.S. Pat. No. 4,296,731). See also, e.g., the photovoltaic tracking system commercialized under the trade name SUNFLOWER™ by Energy Innovations, Pasadena, Calif.
One approach in the prior art has been to develop a set of concentrating collectors, which articulate individually while also articulating en masse, as in Diggs, U.S. Pat. No. 4,187,123.
A recent variation on this approach is to place two rows of collectors in a frame where they articulate approximately in place, such as in Fukuda, U.S. Pat. No. 6,079,408. Such an approach packages a tracking concentrator into a form that is approximately flat.
Bugash et al, U.S. Pat. No. 4,365,617, disclose a reflective solar heating system whose collectors articulate in place.
It has been known previously in the art that a frame around the perimeter of a solar tracking system helps to be able to support the individual photovoltaic elements (see, e.g., the photovoltaic tracking system commercialized under the trade name SOLAROPTIMUS by Conergy, Hamburg, Germany, and International Application Publication No. WO 2006/120475).
Framing around the perimeter of a solar panel can limit packing density of solar panels and/or make the panels less aesthetically pleasing. However, sparse packing can make it easier for concentrator modules to operate without shading each other through a larger portion of the day and of the year, allowing a cost-effective use of the individual concentrators by increasing their overall daily exposure to sunlight.
Many consumers have traditional solar panel mounting structures (e.g., rails and the like) in place and would like to use such existing mounting structures instead of investing in new mounting structures. Retrofitting new and innovative solar panels to traditional solar panel mounting structures can be a significant technical hurdle in making such new panels a practical reality.
A technical challenge with respect to developing innovative solutions around articulating concentrator modules is that many mounting locations such as rooftops and the like tend to have uneven surfaces which can cause the concentrators to bind to an undue degree when the modules articulate in tilt and/or tilt.
With respect to concentrating optics, a need exists to provide a concentrating module with one or more secondary optics such that the optics can withstand one or more environmental stresses such as vibration (e.g., during manufacturing and/or use), thermal and/or physical shock, particle contamination such as dust, combinations of these, and the like.